JP2006143506A - Method for cutting glass substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the occurrence of cutting failures in a method for cutting a glass substrate for constituting a liquid crystal panel. <P>SOLUTION: A seal layer 30 is formed on a first glass substrate 10 in such a manner that it includes a straight line part parallel to a line on which a scribe line SL is formed. Then, a dummy seal layer 30D is formed on the first glass substrate 10 in such a manner that it is in line symmetry with only the straight line part of the seal layer 30 with respect to the line on which the scribe line SL is formed. Further, a second glass substrate 20 is integrally stuck on the first glass substrate 10 through the seal layer 30 and the dummy seal layer 30D so as to form a laminated body 1. Thereafter, the laminated body 1 is cut and separated into each liquid crystal panel by subjecting each of the first and second substrates 10, 20 constituting the laminated body 1 to a scribing process and a breaking process. Lastly, liquid crystal is filled in the liquid crystal injection area 31 and sealed with a sealing material such as resin. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for cutting a glass substrate, and more particularly to a method for cutting a glass substrate constituting a liquid crystal panel.

  In recent years, with the spread of portable electronic devices such as mobile phones and digital cameras, the demand for liquid crystal display devices is increasing. Next, an outline of a manufacturing process of a liquid crystal panel according to a conventional example used in such a liquid crystal display device will be described with reference to the drawings. FIG. 11 is a flowchart showing a manufacturing process of a liquid crystal panel according to a conventional example.

  As shown in FIG. 11, first, in step A1, two glass substrates, that is, a glass substrate on which an electronic device such as a TFT (Thin Film Transistor) is formed, and a glass substrate on which a counter electrode is formed are formed. Then, the laminate is formed by pasting together through a seal layer so as to leave a space to be a liquid crystal injection region. Here, the two glass substrates are large glass substrates in which a plurality of liquid crystal panel regions are arranged on a lattice along dicing lines.

  Next, in step A2, a so-called scribe / break process is performed. That is, a scrub line is formed on the glass substrate on the surface side of the laminate using a cutter wheel or the like (scribing step). Thereafter, the laminated body is turned over and a bending stress is applied to the laminated body by hitting with a bar or the like from the back surface side, and the glass substrate on the surface side of the laminated body is cut along a scribe line (break process). Similarly, a scribe process and a break process are performed on the glass substrate on the back side of the laminate. Through these scribing and breaking processes, the laminate is cut and separated into liquid crystal panels having predetermined dimensions.

  Next, in step A3, a liquid crystal is filled in the space between the two glass substrates and sealed with a sealing resin. In step A4, the liquid crystal panel filled with liquid crystal and sealed is washed. Next, in Steps A5 and A6, the liquid crystal panel is incorporated into a module to be a liquid crystal display device, and the module is shipped.

In addition, as a related technical document, the following patent documents are mentioned, for example.
JP 09-080449 A

  With the spread of portable devices in recent years, the miniaturization of liquid crystal display devices and their liquid crystal panels has progressed, and it has become necessary to cut and separate the glass substrate constituting the liquid crystal panel with high precision. . On the other hand, in order to obtain a large number of liquid crystal panels from the same substrate, the increase in the size of the glass substrate is progressing.

  However, when a large glass substrate is cut by the scribe process and the break process as shown in Step A2 of FIG. 11, the cutting stress is biased due to the influence of the seal layer adjacent to the scribe line, and the cutting shape is deteriorated. There was a problem of doing. That is, in the cutting process of the glass substrate, cutting failure occurred.

  Next, the cutting defect of such a glass substrate is demonstrated with reference to drawings. FIG. 12 is a top view showing a glass substrate according to a conventional example. FIG. 13 is an enlarged top view showing a glass substrate cutting method according to a conventional example. FIG. 13 is an enlarged view of a region S2 in the vicinity of a line (a dotted line in the figure) where the scribe line in FIG. 12 is to be formed. The left figure of FIG. 12 shows the glass substrate after the scribing process, and the right figure shows the glass substrate after the breaking process.

  As illustrated in FIG. 12, the first glass substrate 210 and the second glass substrate 220 are bonded to each other through a seal layer 230 to form a stacked body 201. Further, the stacked body 201 is divided by a line (a dotted line in the figure) on which a scribe line SL to be described later is formed. In each of the divided areas, a plurality of liquid crystal panel formation areas 201A are arranged in a grid pattern. The seal layer 230 is formed so as to surround a liquid crystal injection region 231 to be filled later with a liquid crystal and to open a part of the region.

  In addition to the seal layer 230, a dummy seal layer 230D for reinforcing the degree of adhesion between the two glass substrates is formed between the first glass substrate 210 and the second glass substrate 220.

  And as shown in FIG. 13, on the 1st or 2nd glass substrate 210,220 after a scribe process, dummy seal layer 230D is formed along the whole scribe line SL. Then, after the breaking step along the scribe line SL, the first or second glass substrates 210 and 220 are cut and separated by a cutting line 201B which is a groove penetrating them.

  However, particularly in the vicinity of the intersection of the scribe lines SL, the cutting line 201B does not extend linearly along the scribe lines SL, resulting in unintentional irregular cracking of the first or second glass substrate 210, 220. It is formed so as to have a burr 201N. The burr 201N is considered to be caused by uneven cutting stress because the distance between the seal layer 230 and the dummy seal layer 230D with respect to the scribe line SL is not constant. Thus, in the cutting method of the glass substrate which concerns on a prior art example, the cutting defect that the cutting shape of the 1st or 2nd glass substrate 210,220 deteriorated had arisen.

  When each individual liquid crystal panel separated with a cutting defect as described above is incorporated into a module which is a liquid crystal display device, an incorporation defect such as inclination or displacement of the liquid crystal panel has occurred. In addition, the burr 201N part was peeled off or scraped, causing foreign matter to be generated. As a result, the reliability and yield of the liquid crystal display device liquid crystal panel have been reduced. In view of this, the present invention aims to suppress cutting defects in a method for cutting a glass substrate constituting a liquid crystal panel.

  The glass substrate cutting method of the present invention has been made in view of the above-described problems, and includes a linear portion parallel to a line on which a scribe line is to be formed on the first glass substrate. In addition, a dummy seal layer is formed on the first glass substrate so as to be symmetrical with only the straight portion of the seal layer with respect to the line on which the scribe line is to be formed. A step of bonding a second glass substrate to a first glass substrate through a sealing layer and a dummy sealing layer, and forming a laminate composed of the first and second glass substrates; The method includes a step of forming a scribe line on the surface of the substrate, and a step of breaking the glass substrate on which the scribe line is formed.

  In the glass substrate cutting method of the present invention, in the above step, the dummy seal layer is formed on the first glass substrate outside the seal layer formed at the end of the first glass substrate. It is characterized by that.

  Further, in the method for cutting a glass substrate of the present invention, in the above step, the step of forming a scribe line on the surface of the laminate is performed by laser beam irradiation, and the step of breaking the glass substrate on which the scribe line is formed includes: It is performed by pressing a squeegee against the surface of the other glass substrate facing the glass substrate.

  According to the method for cutting a glass substrate of the present invention, the dummy seal layer is formed on the glass substrate so as to be symmetric with respect to only the straight portion of the seal layer with respect to the line on which the scribe line is to be formed. Thereby, in the breaking process, the deviation of the cutting stress with respect to the scribe line is eliminated as much as possible, and the generation of burrs resulting from unintentional irregular cracking of the glass substrate as seen in the conventional example is suppressed as low as possible. That is, cutting defects due to deterioration of the cutting shape of the glass substrate are suppressed as much as possible.

  The scribe line is formed by laser beam irradiation. Therefore, generation | occurrence | production of the cutting waste seen at the time of formation of the scribe line by a cutter can be suppressed. Moreover, the break process of the glass substrate in which the scribe line was formed is performed by pressing a squeegee against the surface of the other glass substrate facing the glass substrate. Therefore, the cut shape of the glass substrate can be brought into a better state as compared with the case of a break by hitting using a bar (so-called chopper break).

  In addition, since the cutting failure due to the worsening of the cutting shape is suppressed, the liquid crystal panel has a fixed shape. Therefore, when the liquid crystal panel is incorporated in a module which is a liquid crystal display device, it is incorporated in the conventional example. Defects can be avoided as much as possible. As a result, the reliability and yield of the liquid crystal display device are improved.

  Next, a method for cutting a glass substrate according to an embodiment of the present invention will be described. In the present embodiment, the glass substrate to be cut is a laminate composed of two glass substrates. First, a laminate composed of two glass substrates to be cut will be described with reference to the drawings. 1, 3 and 4 are top views showing the glass substrate according to the present embodiment. 2 is a cross-sectional view taken along line XX in FIG.

  As shown in FIG. 1, a large-sized first glass substrate 10 and a second glass substrate 20 are bonded together to form a laminate 1. In the first and second glass substrates 10 and 20, a plurality of liquid crystal panel formation regions 1A surrounded by lines (dotted lines in the figure) on which scribe lines SL to be described later are to be formed are arranged on a lattice. Yes. The first and second glass substrates 10 and 20 are bonded to each other through a seal layer 30 and a dummy seal layer 30D as adhesives so that the liquid crystal panel formation region 1A overlaps. Further, as shown in FIG. 2, a region surrounded by the seal layer 30 between the first glass substrate 10 and the second glass substrate 20 becomes a liquid crystal injection region 31 that is filled later with the liquid crystal 80. A space is formed.

  Next, the formation process of the laminated body 1 as described above will be described with reference to FIGS. First, the sealing layer 30 is formed on the first glass substrate 10 so as to surround the liquid crystal injection region 31 and to have an opening that locally opens the region. The seal layer 30 is formed so as to include a straight line portion parallel to a line (a dotted line in the figure) on which a scribe line SL to be described later is formed. The sealing layer 30 described above is made of a resin having a function as an adhesive.

  Further, a dummy seal layer 30 </ b> D that reinforces the degree of adhesion to the first and second glass substrates 20 is formed outside the liquid crystal injection region 31 on the first glass substrate 10. The dummy seal layer 30 </ b> D is formed so as to be symmetric with respect to only the straight portion of the seal layer 30 with respect to the line on which the scribe line SL is to be formed. That is, the dummy seal layer 30 </ b> D is not formed at a position facing a non-linear portion (curved portion) of the seal layer 30 across a line (a dotted line in the figure) where a scribe line SL to be described later is to be formed. The dummy seal layer 30 </ b> D described above is preferably made of the same resin as the seal layer 30 and is formed with the same width and thickness as the seal layer 30.

  And the 2nd glass substrate 20 is bonded together on the 1st glass substrate 10 through the seal layer 30 and the dummy seal layer 30D. Here, a liquid crystal injection region 31 that is a space surrounded by the seal layer 30 is formed between the first glass substrate 10 and the second glass substrate 20.

  In addition, as shown in FIG. 3, in the stacked body 1, the seal layers 30 constituting the sides of the adjacent liquid crystal injection regions 31 are symmetrical with respect to a line (a dotted line in the figure) where a scribe line is to be formed. May be formed. In this case, the dummy seal layer 30 </ b> D is formed only in the end region (so-called dummy glass region) of the first glass substrate 10. That is, the dummy seal layer 30 </ b> D forms a seal layer 30 that forms an outer side of the liquid crystal injection region 31 at the end with respect to a line on which the scribe line SL is formed at the end of the first glass substrate 10. And is formed outside the liquid crystal injection region 31 at the end.

  As shown in FIG. 4, the laminated body 1 described above is cut into individual liquid crystal panels 1P and separated by a scribing process and a breaking process described later. Next, the cutting method of the laminated body 1 which consists of the 1st and 2nd glass substrates 10 and 20 mentioned above is demonstrated with reference to drawings. 5 to 7 are perspective views showing a glass substrate cutting method according to this embodiment. 5 to 7, the illustration of the liquid crystal injection region 31 between the first and second glass substrates 10 and 20 is omitted.

  As shown in FIG. 5, the laminated body 1 is prepared so that the 1st glass substrate 10 may become an upper layer. Then, the scribe line SL is formed on the first glass substrate 10 of the stacked body 1 along the line on which the scribe line SL is to be formed by cutting using the cutter 40. The scribe line SL formed at this time is a vertical crack (crack) generated by the biting of the blade 40 of the cutter 40 with a predetermined pressure and speed into the glass substrate 10, that is, a median crack 100 is continuously formed. It is formed. Hereinafter, the process of forming the scribe line SL is referred to as a scribe process.

Further, as shown in FIG. 6, the scribing process may be performed by laser beam irradiation using a laser irradiator 40A. In other words, the glass substrate 10 at that location is rapidly heated by laser beam irradiation along the line on which the scribe line SL is to be formed. Then, the glass substrate of the said location is rapidly cooled using a cooler, a cooling fluid, etc. (not shown). Here, the laser beam irradiation is not particularly limited, but a CO ₂ laser is preferably used. When a cooling fluid (not shown) is used, water or other liquid is used as the cooling fluid. Due to these rapid heating and cooling, vertical cracks are generated in the glass substrate 10 and scribe lines SL are formed.

  In such a scribing process by laser beam irradiation, unlike the scribing process by cutting using the cutter 40, no cutting waste is generated when the scribe line SL is formed. Therefore, the cutting waste does not adhere on or between the first or second glass substrates 10 and 20. Therefore, the first or second glass substrate 10 or 20 is not soiled or damaged due to the above-mentioned cutting waste.

  Next, as shown in FIG. 7, the laminated body 1 is inverted so that the first glass substrate 10 on which the scribe line SL is formed becomes a lower layer. Then, the squeegee 50 is pressed with a predetermined pressure along the line of the second glass substrate 20 corresponding to the scribe line SL. Thereby, a bending stress is applied to the laminated body 1, the scribe line SL of the first glass substrate 10, that is, the median crack 100 is further expanded, and the first glass substrate 10 is cut. Hereinafter, such a cutting process will be referred to as a breaking process.

  The breaking process described above is a so-called soft breaking method in which the squeegee 50 is pressed against the second glass substrate 20. In the breaking process by this method, bending stress to the laminated body 1 is not abruptly applied. Therefore, it is possible to suppress as much as possible that cutting that significantly deteriorates the cutting shape, that is, simultaneous cutting of the first and second glass substrates 10 and 20 occurs.

  Next, details of the breaking step will be described with reference to the drawings. 8 and 9 are cross-sectional views taken along the line SS of FIG. 8 shows a state before the squeegee 50 is pressed against the second glass substrate 20, and FIG. 9 shows a state during or after the squeegee 50 is pressed against the second glass substrate 20. Shows the state. 8 and 9, the liquid crystal injection region 31 between the first and second glass substrates 10 and 20 is not shown.

  As shown in FIG. 8, the median crack 100 is formed with a depth that does not penetrate the first glass substrate 10 before the squeegee 50 is pressed against the second glass substrate 20.

  As shown in FIG. 9, when the squeegee 50 is pressed onto the line of the second glass substrate 20 corresponding to the scribe line SL, bending stress is applied to the laminate 1. Due to this bending stress, not only the second glass substrate 20 but also the first glass substrate 10 is deformed so that the squeegee 50 is pushed out in the pressing direction.

  The bending stress becomes a tensile stress with respect to the surface of the first glass substrate 10. This tensile stress acts so as to tear the median crack 100 on the surface of the first glass substrate 10 and extends the depth of the median crack 100. That is, the median crack 100 (that is, the scribe line SL) of the first glass substrate 10 extends toward the second glass substrate 20. The extension of the median crack 100 generates an extension crack 101 that penetrates the first glass substrate 10 along the scribe line SL, and the first glass substrate 10 is cut along the scribe line SL.

  The breaking step may be performed by hitting the second glass substrate 20 with a squeegee or a bar with a predetermined acceleration such that a predetermined impact is applied to the second glass substrate 20. However, in this case, compared to the breaking process by pressing the squeegee 50, the cutting shape is deteriorated and the cutting accuracy is easily reduced.

  Further, the breaking step may be performed by moving a roller (not shown) while pressing the second glass substrate 20 while applying a predetermined pressure in place of the squeegee 50.

  Similarly, the scribe process and the break process described above are also performed on the second glass substrate 20. That is, after the laminated body 1 is inverted so that the second glass substrate 20 becomes an upper layer, the scribe line SL is formed on the line of the second glass substrate 20 in the same manner as the first glass substrate 10. Here, the scribe line SL formed on the second glass substrate 20 is formed on a line overlapping the scribe line SL formed on the first glass substrate 10.

  And the laminated body 1 is reversed so that the 2nd glass substrate 20 in which the scribe line SL was formed becomes a lower layer, from the surface of the 1st glass substrate 10 along the line corresponding to the scribe line SL, The squeegee 50 is pressed with a predetermined pressure. Thereby, the scribe line SL of the second glass substrate 20, that is, the median crack 100 further expands, and the second glass substrate 20 is cut. Thus, the laminated body 1 composed of the first and second glass substrates 10 and 20 is cut and separated along the scribe line SL in the first direction.

  Further, although not shown, the scribing process and the breaking process for the first and second glass substrates 10 and 20 described above are performed along the second direction of the plane of the laminate 1. As a result, the large first and second glass substrates 10 and 20 are cut and separated into individual liquid crystal panels 1P as shown in FIG. Further, the liquid crystal injection region 31 of FIG. 4 is filled with liquid crystal 80, and the region is sealed with a sealing material 32 such as resin. A liquid crystal panel is thus completed.

  Here, the cut shape of the glass substrate of the laminated body 1 cut by the scribing process and the breaking process described above does not have an irregular crack as seen in the conventional example, and therefore has no burrs. Next, details of the cut shape will be described with reference to the drawings.

  FIG. 10 is an enlarged top view showing the glass substrate cutting method according to the present embodiment. FIG. 10 is an enlarged view of a region S1 in the vicinity of a line (a dotted line in the figure) where the scribe line in FIG. 1 is to be formed. 10 shows the first or second glass substrate 10 or 20 after the scribing process, and the right figure shows the first or second glass substrate 10 or 20 after the breaking process. .

  As shown in FIG. 10, on the first or second glass substrate 10 or 20 after the scribe process, only the straight portion of the seal layer 30 and the dummy seal layer 30D are formed symmetrically with respect to the scribe line SL. Has been. That is, the shortest distance A between the straight portion of the seal layer 30 and the scribe line SL is equal to the shortest distance B between the dummy seal layer 30D and the scribe line SL. Further, the dummy seal layer 30 </ b> D is not formed at a location facing the non-linear portion (curved portion) of the seal layer 30 across the scribe line SL.

  Due to the positional relationship between the scribe line SL, the seal layer 30 and the dummy seal layer 30D as described above, the cutting stress is applied to the first or second glass substrate 10 or 20 during the glass substrate break process of the laminate 1. The scribe line SL is added to both sides of the scribe line SL without being biased (in the left-right direction), that is, symmetrical to the scribe line SL. Therefore, the scribe line SL is appropriately cut without generating burrs generated as a result of unintentional irregular cracking of the glass substrate as in the conventional example, and the cut line 1B is formed. That is, the cutting line 1B is formed without causing a deviation from the scribe line SL as much as possible.

  In this way, the laminated body 1 can be cut and separated into individual liquid crystal panels 1P while suppressing the deterioration of the cutting shape of the glass substrate as seen in the conventional example, that is, cutting failure as much as possible. Therefore, when the individual liquid crystal panels 1P separated as described above are incorporated into a module which is a liquid crystal display device, it is possible to suppress assembling defects such as inclination and displacement of the liquid crystal panel as much as possible as compared with the conventional example. it can. As a result, the reliability and yield of the liquid crystal display device liquid crystal panel are improved.

It is a top view which shows the glass substrate which concerns on embodiment of this invention. It is sectional drawing along the XX line of FIG. It is a top view which shows the glass substrate which concerns on embodiment of this invention. It is a top view which shows the glass substrate which concerns on embodiment of this invention. It is a perspective view which shows the cutting method of the glass substrate which concerns on embodiment of this invention. It is a perspective view which shows the cutting method of the glass substrate which concerns on embodiment of this invention. It is a perspective view which shows the cutting method of the glass substrate which concerns on embodiment of this invention. It is sectional drawing along the SS line | wire of FIG. It is sectional drawing along the SS line | wire of FIG. It is an enlarged top view which shows the cutting method of the glass substrate which concerns on embodiment of this invention. It is a flowchart which shows the manufacturing process of the liquid crystal panel which concerns on a prior art example. It is a top view which shows the glass substrate which concerns on a prior art example. It is an enlarged top view which shows the cutting method of the glass substrate which concerns on a prior art example.

Explanation of symbols

1,201 Laminate 1P Liquid crystal panel 1A, 201A Liquid crystal panel formation region 10, 210 First glass substrate 20, 220 Second glass substrate 30, 230 Sealing material 31, 231 Liquid crystal injection region 40 Cutter 40A Laser irradiator 50 Squeegee 80 LCD 100 Median crack 101 Stretch crack SL Scribe line

Claims (3)

Forming a seal layer on the first glass substrate so as to include a linear portion parallel to a line on which a scribe line is to be formed;
Forming a dummy seal layer on the first glass substrate so as to be symmetrical with only the straight portion of the seal layer with respect to a line on which the scribe line is to be formed;
Bonding the second glass substrate to the first glass substrate via the seal layer and the dummy seal layer, and forming a laminate composed of the first and second glass substrates;
Forming a scribe line on the surface of the laminate;
And a step of breaking the glass substrate on which the scribe line is formed. 2. The glass substrate according to claim 1, wherein the dummy seal layer is formed on the first glass substrate outside the seal layer formed at an end portion of the first glass substrate. Cutting method. The step of forming a scribe line on the surface of the laminate is performed by laser beam irradiation,
The glass substrate according to claim 1, wherein the step of breaking the glass substrate on which the scribe line is formed is performed by pressing a squeegee or a roller against the surface of the other glass substrate facing the glass substrate. Cutting method.

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